Aspects of neonatal metabolism of trace metals

Hypozincemia in Chronic Hepatitis C Is Improved with Viral Clearance by Direct-acting Antiviral Agents

Objective Hypozincemia is a decrease in the serum zinc level of patients with hepatitis C and often requires zinc supplementation to improve the hepatic function. Our previous study showed the efficacy of direct-acting antiviral agent (DAA) treatment on serum zinc levels in patients with hepatitis C without zinc supplementation. In this study, we aimed to prospectively examine factors related to the improvement of serum zinc levels of patents with hepatitis C with DAA treatment. Methods Fifty-three patients with hepatitis C treated with DAAs between March 2018 and February 2019 at a university medical center were divided into two groups based on their initial serum level: the zinc deficiency group (n=43, <80 μg/dL) and the normal zinc group (n=10, ≥80 μg/dL). Their serum zinc levels and clinical parameters were measured before DAA treatment, at the end of treatment and 12 weeks post-treatment. Results All 53 patients achieved a sustained viral response to DAAs at the end of treatment and at follow-up. There was a significant increase in the serum zinc level from baseline to follow-up in the zinc deficiency group but not in the normal zinc group. The change in serum albumin was the only factor contributing to the observed increase in serum zinc levels by a multiple regression analysis. Conclusion DAA treatment in patients with hepatitis C improved hypozincemia due to the restored function of serum albumin, which binds to about 60% of serum zinc, upon the amelioration of the hepatitis C infection.

Correlation of serum zinc levels with pathological and laboratory findings in patients with nonalcoholic fatty liver disease

OBJECTIVE

Chronic liver diseases are associated with zinc (Zn) deficiency. However, no previous studies have examined the relationship between serum Zn levels and hepatic pathological findings in patients with nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the serum Zn levels in NAFLD patients based on pathological/laboratory findings.

METHODS

We evaluated a total of 191 NAFLD patients who underwent liver biopsy with the goal of identifying laboratory markers and pathological findings associated with serum Zn levels.

RESULTS

Zn levels significantly decreased along with progression of hepatic fibrosis (P = 0.039), but there were no significant differences among inflammatory grades. Zn levels were most strongly correlated with albumin levels (r = 0.410, P < 0.001). In addition, Zn levels were significantly correlated with homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.284, P < 0.001), hyaluronic acid (r = -0.230, P < 0.001), branched chain amino acid/tyrosine molar ratio (BTR) (r = 0.278, P < 0.001), FIB-4 index (r = -0.238, P < 0.001), and NAFLD fibrosis score (NFS) (r = -0.261, P < 0.001). In multivariate analysis, albumin [odds ratio (OR), 9.244 (per 1 g/dL decrease) [95% confidence interval (CI), 2.261-32.744]; P < 0.001], BTR [OR, 1.545 (per 1 decrease) (95% CI, 1.115-2.140); P = 0.009], and HOMA-IR [OR, 1.048 (per 1 increase) (95% CI, 1.019-1.167); P = 0.028] were significantly associated with Zn deficiency.

CONCLUSION

The progression of liver fibrosis, but not inflammation, is associated with lower serum Zn levels in biopsy-proven NAFLD patients. Serum Zn levels were correlated with nutrition markers and insulin resistance.

Zinc and infant nutrition

Zinc is essential for a wide variety of cellular processes in all cells. It is a critical dietary nutrient, particularly in the early stages of life. In the early neonatal period, adequate sources of zinc can be obtained from breast milk. In rare circumstances, the mammary gland produces zinc deficient milk that is potentially lethal for exclusively breast-fed infants. This can be overcome by zinc supplementation to the infant. Alterations to key zinc transporters provide insights into the mechanisms of cellular zinc homeostasis. The bioavailability of zinc in food depends on the presence of constituents that may complex zinc. In many countries, zinc deficiency is a major health issue due to poor nourishment. Young children are particularly affected. Zinc deficiency can impair immune function and contributes to the global burden of infectious diseases including diarrhoea, pneumonia and malaria. Furthermore, zinc deficiency may extend its influence across generations by inducing epigenetic effects that alter the expression of genes. This review discusses the significance of adequate zinc nutrition in infants, factors that influence zinc nutrition, the consequences of zinc deficiency, including its contribution to the global burden of disease, and addresses some of the knowledge gaps in zinc biology.

Maternal--neonatal serum selenium and copper levels in Greeks and Albanians

AIM

To evaluate selenium (Se) and copper (Cu) concentrations in Greek and Albanian immigrant mothers and in the cord blood of their newborns.

SUBJECTS AND METHODS

From 1118 Greek and 820 Albanian mothers and from the cord blood of their neonates blood was obtained for Se and Cu measurement. Se and Cu concentrations were determined in sera with graphite furnace atomic absorption spectroscopy (GFAAAS) and atomic absorption spectrometry, respectively. In all, 30 days' nutrient intakes were evaluated in both groups.

RESULTS

Animal protein, Se and Cu intakes were poor in the Albanians vs the Greeks (P < 0.001). Se concentrations in the Greek mothers (68.3 +/- 8.5 microg/l) and in their newborns (37.02 +/- 8.9 microg/l) were found higher as compared with those in Albanian mothers (37.4 +/- 9.9 microg/l) and in their newborns (34.3 +/- 9.1 microg/l) (P < 0.001). Cu levels were also found higher (P < 0.001) in the Greek mothers (1687 +/- 353 microg/l) and in their neonates (449 +/- 87 microg/l) compared with those in the Albanian mothers (959 +/- 318 microg/l) and in their newborns (229 +/- 67 microg/l). Additionally, 31.5% of neonates born to Albanian women with Se concentrations less than 28 microg/l had higher Se levels (P < 0.01) than their mothers.

CONCLUSIONS

The low Se and Cu levels evaluated in the Albanian mothers and their newborns could be related to their poor animal protein intake which could be the consequence of their low socioeconomic status. As an effective preventive measure, accurate dietetic strategies to assess the requirements of pregnant immigrant women for trace elements may be planned in Greece.

Characterization of iron, copper and zinc levels in the colostrum of mothers of term and pre-term infants before and after pasteurization

Pasteurization is a thermal treatment applied to the milk used in human milk banks so as to provoke the thermic inactivation of pathogenic micro-organisms, with the aim of avoiding contamination of milk that will be offered to new-born infants in clinical conditions very often demanding special care. The literature has very little data available relating to the effect of pasteurization on the concentration of oligo-elements in human milk. The objective of this study was to evaluate the effect of pasteurization on the concentrations of iron (Fe), copper (Cu) and zinc (Zn) in the colostrum of mothers of pre-term (PT) and term (T) infants. Samples were collected from the day of birth to the seventh day after birth. The oligo-elements were analyzed using the total reflection X-ray fluorescence technique with synchrotron radiation. The following results of Fe, Cu and Zn (means +/- SD) were obtained for the PT and T colostrum samples, non-pasteurized and pasteurized, respectively: PT: 1.96 +/- 0.73 mg/l Fe/Zn/5.39 +/- 2.73 mg/l Zn; T: 1.71 +/- 1.01 mg/l Fe/1.46 +/- 0.99 mg/l Fe, 0.54 +/- 0.29 mg/l Cu/0.49 +/- 0.19 mg/l Cu, 6.97 +/- 2.82 mg/l Zn/6.75 +/- 2.62 mg/l Zn. There was a significant reduction in the levels of Fe, Cu and Zn in the samples of pasteurized colostrum. These results suggest that, despite the observance of a diminution in the levels of Fe, Cu and Zn in the samples of pasteurized colostrum, the values fell within the acceptable range for the specific nutritional needs of new-born infants during this period of lactation.

Serum zinc and copper levels in the maternal blood and cord blood of neonates

Estimation of serum zinc and copper in the maternal blood and cord blood of neonates was carried out to correlate the trace metals in the neonates and their mothers in relation to gestational age and birth weight. Sixty-five healthy neonates, both term and preterm and their mothers were selected. This cross sectional study was done at Azimpur Maternity Centre, Dhaka Medical College Hospital and Chemistry Division, Atomic Energy Centre, Dhaka, Bangladesh from July 1997 to June 1998. The estimation of trace metals was carried out by Atomic Absorption Spectrophotometry (AAS). The mean serum zinc levels in the maternal blood and cord blood were 0.47 +/- 0.24 microgram/ml and 0.85 +/- 0.33 microgram/ml respectively and the mean copper levels in the maternal blood and cord blood were 1.37 +/- 0.62 micrograms/ml and 0.31 +/- 0.32 microgram/ml respectively. Cord blood zinc level was significantly higher and cord blood copper level was significantly lower than the corresponding maternal blood levels. There was no significant correlation between gestational age and serum zinc levels in the cord or maternal blood. But significant inverse correlation was found between gestational age and serum levels of copper in the maternal and cord blood.

Nutritional zinc balance in extremely low-birth-weight infants

BACKGROUND

Zinc is important for metabolism, cell growth, immunity, and defense against oxygen radicals. Extremely low-birth-weight (< 1000 g) infants have higher nutritional needs, but information on zinc is scarce. The authors performed nutritional balances in 10 infants with birth weights of 500 to 999 g and who were fed with fortified human milk.

METHODS

The authors collected infant feces, urine, and blood and human milk samples during 72 hours at 7 and 12 weeks of age. Zinc concentration was measured by inductively coupled plasma-mass spectrophotometry, atomic emission spectrophotometry, and instrumental neutron activation analysis.

RESULTS

Mean (SD) intake via human milk was 379 (+/- 373) microg x kg(-1) x d(-1) during both balances. Urinary excretion was high at 7 weeks of age, decreased to half at 12 week, and was negatively correlated (P < 0.01) with weight gain. Mean absorption was slightly positive at 7 weeks of age but zero or negative in most infants at 12 weeks of age. Retention was negative in all infants at both observation periods, except in one infant during the second balance. Clinical zinc deficiency developed in one infant at 12 weeks of age.

CONCLUSIONS

Zinc balances in extremely low-birth-weight infants are highly variable and usually negative. Controlled trials are needed to assess need for and benefits and risks of zinc supplementation.

Concentrations of trace elements in sera of newborns, young infants, and adults

Concentrations of trace elements in newborns, infants, and adults may be significantly different from each other. Serum trace element reference ranges for different age groups are of value for diagnostic purposes. Inductively coupled plasma-mass spectrometry was applied to the determination of the 21 trace elements Ba, Be, Bi, Ca, Cd, Co, Cs, Cu, La, Li, Hg, Mg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, TI, and Zn in a total of 117 sera of individuals representing different age groups. After microwave-assisted acid digestion with high-purity reagents, 20 umbilical cord sera, 5 sera of fully breast-fed infants, 6 sera of formula-fed infants, 66 sera of patients suffering internal diseases, and 20 sera of healthy blood donors were analyzed for trace elements. One serum and two whole-blood reference materials were analyzed for quality control. Experimental concentrations were in good agreement with certified values. Umbilical cord serum concentrations of the essential elements Ca, Co, Cu, and Mg and of the nonessential and toxic elements Ba, Be, Li, Pb, and Sb were elevated compared to the elemental concentrations in the sera of infants and adults. Serum levels of Ba, Ca, Co, Mn, Pb, and Sb of infants were much higher and serum Cu was significantly lower than in adults. Serum Cu increased significantly with age (newborns: 353 microg/L; infants: 755 microg/L; healthy adults: 810 microg/L), whereas for other trace elements no age-dependence could be established.

Caeruloplasmin isoforms in Wilson's disease in neonates

AIM

To investigate the neonatal diagnosis of Wilson's disease from caeruloplasmin isoforms in cord blood.

METHODS

Serum caeruloplasmin isoforms were measured in 5-10 ml cord blood from 10 fresh umbilical cords using sodium dodecyl polyacrylamide gel electrophoresis (SDS PAGE) and western blotting and analysed by densitometry. Total caeruloplasmin concentrations were determined by nephelometry and caeruloplasmin oxidase by p-nitrophenyldiamine.

RESULTS

Although total caeruloplasmin concentrations are reduced in neonates, the plasma isoform was significantly reduced or absent in patients with Wilson's disease. Sera from healthy neonates and from those with Wilson's disease had reduced biliary isoforms.

CONCLUSION

Identification of caeruloplasmin isoforms may be a marker for Wilson's disease in neonates.

Properties of human milk and their relationship with maternal nutrition

The composition of human milk varies over the course of lactation and in each individual. The volume of breast milk produced is related to the weight of the infant. Human milk is markedly different from cows' milk, both in terms of macronutrients and micronutrients. This includes the types of fatty acids present and factors affecting their absorption. The types of proteins present and their relative proportions and both qualitative and quantitative differences in the non-protein nitrogen fraction. There is much less lactose in cows' milk than breast milk and the oligosaccharide fraction is very different. Their are major differences in content and absorption rates of vitamins and minerals from breast milk compared to cows' milk or formula milk. Vitamin D and vitamin K status are possible problems for the breast-fed infant in certain circumstances. The nutritional status of the mother appears to influence fat concentration and thus the energy content of breast milk as well as its fatty acid composition and immunological properties. There is no coherent evidence, however, that the protein or lactose concentrations are greatly affected. There is some evidence that the concentration of vitamins in the breast milk are influenced by the mother's intake. Minerals are less variable, with the exception of selenium. The response of the infant to human and formula milk differs with respect to endocrine function, stool motility, immune function and renal function. Infant formula milks are designed to mimic human milk as much as possible, but this is unlikely to ever be completely successful. A number of important compositional differences between human milk and formula milk remain. This includes the types and proportions of fatty acids present (which may be of developmental importance), the nature of the non-protein nitrogen component (also possible developmental importance) and the presence of immunoglobulins and fibronectin (which may protect the infant against infection).